Rat pups exposed to CBD in the womb weighed less at birth, gained less weight before weaning, and showed subtle changes in early neurodevelopmental behaviors at higher doses.
Pregnant individuals considering CBD use, healthcare providers, researchers studying prenatal cannabinoid exposure
Both CBD doses reduced birth weight and pre-weaning weight gain
What the researchers found
Prenatal CBD exposure (5 and 10 mg/kg daily) resulted in lower birth weight and reduced weight gain before weaning. The higher dose (10 mg/kg) decreased homing behavior performance and produced subtle changes in righting reflex during the first postnatal week. Differences resolved by weaning at day 21.
Why it matters
CBD is increasingly used during pregnancy for nausea and pain, often perceived as safe because it is non-intoxicating. This animal study suggests prenatal CBD may affect fetal growth and early development, even if effects appear transient.
The numbers in context
Doses: 5 and 10 mg/kg/day from gestational day 6 to 20. Both doses reduced birth weight and pre-weaning weight gain. 10 mg/kg decreased homing behavior and altered righting reflex in the first postnatal week. No effects on gait, negative geotaxis, or grip strength. Differences resolved by postnatal day 21.
How the study worked
Pregnant rats received daily CBD injections (5 or 10 mg/kg IP) from gestational day 6 to 20. Researchers tracked litter health parameters and conducted neurodevelopmental behavioral tests including homing behavior, righting reflex, negative geotaxis, gait, and grip strength.
What this study cannot tell us
Animal study with IP injection, which does not match how humans use CBD. Only two doses tested. Effects resolved by weaning, raising questions about long-term significance. Rat development does not perfectly parallel human development.
How to read the evidence
Preliminary: single animal study with IP injection route and limited dose range
When this study was published
Published in 2025
The bigger picture
The growing perception of CBD as harmless may lead more pregnant people to use it. While this animal study shows effects that resolved by weaning, the developmental window when these changes occur is critical for brain maturation in both rats and humans.
Questions still open
- Do these transient developmental changes have any long-term consequences? Would oral CBD produce the same effects? How do these doses translate to human CBD use during pregnancy?
Common questions
Is it safe to use CBD during pregnancy?
Did the effects last?
Read the original research
Neurodevelopmental outcomes following prenatal cannabidiol exposure in male and female Sprague Dawley rat offspring.
Neuroscience, 598, 72-83
Citation
Baccetto, Sarah L; Black, Tallan; Barnard, Ilne L; Macfarlane, Leah M; Sanfuego, Genre B; Laprairie, Robert B; Howland, John G. (2025). Neurodevelopmental outcomes following prenatal cannabidiol exposure in male and female Sprague Dawley rat offspring.. Neuroscience, 598, 72-83. https://doi.org/10.1016/j.neuroscience.2025.12.018
Explore the wider topic
- How to Talk to Your Teenager About Weed (Without Losing Them)
- My Kid's Friends Smoke Weed: A Parent's Guide
- I Smoke Weed But Don't Want My Kids To: Navigating the Hypocrisy
- Quitting Weed as a Parent: Why It Is the Hardest and Most Important Quit
- Quitting Weed as a Teen or Young Adult
- My Kid Is Smoking Weed: A Parent's Guide